Wile we're at it, I think that, following the same definition of the
Antarctic Ocean, the Bouvet Island (54°S) should be considered as part of
Atlantic Ocean, not Antarctica.
The same goes for South Georgia (54°S) and the South Sandwich Islands
(the most southern is 59°27').

Very good. If you are adding a new region, you may also consider
moving FK (Falkland Islands) and SH (Saint Helena) to it.